I'm lost when it comes to fashion? where do i start?

im 16, and i just want to look nice. what sort of colours and shapes shoudl i be wearing? and what should i be wearing i have no idea anymore, i used to be really fashionable but now i just dont know,. i go shopping and i just have no clue what to buy! :( im blonde and pale, im 5'8/9 and a uk size 6 and im pretty shapeless? anythign i can wear to give me curves and make me lok nice for a change? thanks x